This week I ran into a weird problem on my Prusa XL with .2mm hardened nozzles: MatterHackers Build PLA filament worked just fine when doing single color prints, but failed miserably when printing in multiple colors at the same time. Check out this train wreck of a two-color print:
These were printed side-by-side on the PrusaXL, and were a mess of stringing and goo. The filament must be bad or the print settings messed up, right? But printing the two benchies separately worked just fine, and the filament was brand new out of the vaccum packaging. The advice was that the filament wasn't dry enough, but then why would a single-color print work correctly?
The advice from the PrusaXL Facebook group was to take a closer look at the settings, so I ran a temperature tower and stringing test. Oddly, the advice to lower the temperature seemed to be wrong: lower temperatures created more stringing, not less. The other advice was to be meticulous about moisure, so just to remove that as a potential issue the filament was stored overnight in dry boxes before running any more tests.
After much testing with stringing towers, the following modifications to the generic PLA settings did the trick:
That took care of all of the visible stringing, but there it was still an issue when printing multi-color. The individual colors were noticeably better, but strings from one color would get stuck on other colors.
Luckily the YouTube channel 3D Print Dogs had a solution:
Their solution looks like this in the Matter Hackers Build PLA settingsin the Custom G-Code section:
The result was this inlay test went from looking terrible to acceptable. There is still the occasional whisp of filament, but on the whole the multi-color print is greatly improved.
